Make sure you surround yourself with people who cheer you on in the midst of the battle — no matter what it is you may be doing or fighting. Whether it is starting a new business, running a certain race or even fighting for your life like Hall of Fame quarterback Jim Kelly once was, you can’t rely solely on your own strength to get you through.

Here is an edited excerpt from the new book, Kelly Tough, written by the daughter of Jim Kelly, Erin Kelly.

Former teammates Thurman Thomas, Andre Reed and Bruce Smith went from helping raise the Bills’ score back when they all played together to raising my dad’s spirits when they came by the house to give him a sendoff as he left for New York City. He was gearing up for a six-week tour that was to include surgery, pain management, chemotherapy and radiation and it turned out to be very demoralizing. And yet in the throes of a very challenging time, even for one of the NFL’s toughest quarterbacks, all three of them also made the trip to visit him.

I learned a lot from the way all of these former players and my dad’s friends stepped right into his corner and went to battle with him, not on the gridiron as a teammate, but as brother who really loved my dad and put legs on that love (so to speak).

We are not meant to do this life journey alone. We need something bigger than ourselves and we need each other. Every one of us will come against insurmountable circumstances and trials that will cause us to want to give up and call it quits. However, when we have an incredibly strong inner-circle of people who are willing to go to battle with us, absolutely nothing is impossible.

You may not be fighting for your life like Jim Kelly was, but it certainly does show you how vitally important it is to have strong, courageous and like-minded individuals in your corner.

This celebrated and hall of fame athlete was used to being on top for most of his life, and then, in an instant, was fighting to live another day. When reading through the book and talking to those who were close to him, it’s incredible to hear that his inner-circle of loved ones is really what got him through the extreme pain of chemo treatments and the whole process as a whole.

All successful entrepreneurs and business leaders will tell you that a large part of their success is because of the people they surrounded themselves with and those that are on their team. When you feel like all is lost, when you are ready to give up and throw in the towel, it’s amazing the strength you find deep within when your team and those around you believe in you and is right by your side every step of the way.

Even though we may not be fighting against two separate bouts of cancer, we must learn this invaluable lesson from the great Jim Kelly: We are only as strong as the people around us.

Originally Posted on Entrepreneur.com